# Internal:Analytica Reference Guide

These pages offer reference documentation for concepts, features, and functions of Analytica 4.0. At present, it covers only a few of them. For those, it is more detailed and technical than the Analytica User Guide.

Releases of Analytica prior to 4.0 may not offer all the functions and features described here.

## Function Parameter Qualifiers

Details related to defining of user-defined functions, particularly how parameters are declared.

## Statistical Functions and Importance Weighting

Statistical functions compute various quantities that summarize a data sample.

Statistical functions include: Mean, SDeviation, Variance, Skewness, Kurtosis, GetFract, Correlation, RankCorrel, Frequency, Probability, ProbBands, Statistics, PDF and CDF.

Several of these appear as uncertainty views in the Analytica result window, and as such, the specifications of these functions apply to the result views as well.

Statistical functions operate over the Run index by default, but all can be applied to any other index (a feature new to 4.0). In addition, all statistical functions support weighted usages, where non-equal weights are assigned to each sample point (also new to 4.0).

## Distribution Functions

Random and Shuffle functions.

Over parameter: For generate independent samples over an index (or over several indexes), e.g.: Normal(popEst,popEstErr,over:Country)

Extension: Uniform( Integer:true ) -- uniform integer distribution

Extension: LogNormal: Can now define by specifying any two: geometric mean, Arithmetic mean, geometric stddev, arithmetic stddev.

Truncate

## Date Functions

New to 4.0: DateAdd, DatePart, MakeDate

## OLAP and Database Functions

New to 4.0: MdxQuery

New 4.0 extensions: MDTable

## System Functions

New to 4.0: RunConsoleProcess, GetRegistryValue, ShowPdfFile,

## Array Functions and Operators

Functions New to 4.0: PositionInIndex.

Operators new to 4.0: @ (position operator), A[I=x] := expr (slice assignment), (expr)[A=x] operator

New 4.0 Extensions: Rank

## Library functions

Distributions: MultiUniform, Uniform_spherical, Smooth_fractile, Erlang, Pareto, Rayleigh, Lorenzian, NegBinomial, InverseGaussian, Wald, Warp_dist